build: Install headers for native builds

When building a game that has been ported to Linux using DXVK Native,
these headers are necessary to provide the Direct3D and DXVK APIs.

Signed-off-by: Simon McVittie <smcv@collabora.com>

include/native/meson.build

@@ -0,0 +1,18 @@
+install_subdir(
+  'directx',
+  install_dir: get_option('includedir') / 'dxvk',
+  strip_directory: true,
+)
+
+install_subdir(
+  'windows',
+  install_dir: get_option('includedir') / 'dxvk',
+  strip_directory: true,
+)
+
+install_headers(
+  'wsi/native_wsi.h',
+  'wsi/native_sdl2.h',
+  'wsi/native_glfw.h',
+  subdir: 'dxvk/wsi',
+)

meson.build

@@ -185,4 +185,8 @@ dxvk_version = vcs_tag(
   output: 'version.h',
 )
 
+if platform != 'windows'
+  subdir('include/native')
+endif
+
 subdir('src')